In many industries, abrasive brushes are used to prepare and/or to finish materials. Brushes have been applied, for example, to: generate satin finishing of metal; deburr metal products; finish wood materials; conduct flash removal from plastics; facilitate oxide removal from metallic materials; and, to clean and/or etch glass. To accomplish these, and other applications, industrial brushes have been provided with a variety of types of bristles including bristles made from: polyesters, polyethylene, nylon and polypropylene strands or fibres. The bristle material may, optionally, be impregnated with abrasive materials. The various types of fibres have found use in a wide variety of applications, to obtain varying effects in surface treatment of articles brought into association with the brush.
For many industrial applications, the brushes are mounted on wheels or rollers which are rapidly spun during a finishing operation. In a typical industrial application, an elongate cylindrical roller having brush material mounted thereon is provided. Material to be treated is then passed along a conveyed path and into engagement with the brush media.
A major concern of the finishing products industry has been the development of convenient, effective, methods for the mounting of brush elements, i.e. fibrous or bristle material, onto industrial finishing rollers, wheels or the like. Other major concerns in the industry have involved the nature of the fibre or bristle mounting within the brush element.
As to brush bristle mounting, many industrial brushes are of one of three types: crimped channel construction; tufted construction; and, products in which individual bristles are mounted tightly packed but spaced independently and not in either tufts or crimped channels, i.e., the bristles form a carpet-like arrangement of individually mounted bristles.
Crimp channel brushes are generally made by securing the base end of the bristles in a metal channel. The channel is usually formed in such a manner that the bristles are held fast, when sides of the channel are forced together or crimped. In some constructions, the bristles are individual strands held in the channel. However, often the bristles are folded in half, and the bent loops are mounted in the channel.
Tufted brushes are very common in both industrial and consumer applications. Tufted brushes are characterized by an anchoring of a group of bristles (the tuft) in a hole or other receptacle in a base material. The tuft is then secured within the receptacle by: heat-bonding; an adhesive; stapling; stitching; or, by some other, similar, means. The size and shape of a tufted brush is defined generally by the design of the base or substrate to which the tufts are attached. The distribution of brush media is determined by the pattern of receptacles in the base, and the number of bristles in each tuft. Such media can be arranged to form a carpet-like bed of bristles.
The third general type of industrial brush comprises a construction wherein bristles are anchored individually, rather than in groups or bunches. Typically, the bristles are anchored in a flexible base that allows the brush media to conform to a variety of configurations. A particularly well-known example of this type of brush is the Brushlon.RTM. line of products (3M, St. Paul, Minn. 55144). Such brushes involve anchoring of bristles in a polymeric bed (resin) either applied to or including a substrate. Such systems form a thick carpet-like bed of bristles. In some applications, the bristles may be directly set in the substrate.
For many industrial applications, the third type of arrangement (individually mounted bristles) is preferred. Reasons include the fact that the construction generally avoids gaps between fibres, which could clog with collected particles. Further, individual bristles are less likely to break, due to good support provided by adjacent bristles or fibres. Also, since the fibres are spread relatively evenly across the work surface, each fibre or bristle, in a localized region, is more likely to be worked to approximately the same extent as other bristles. Thus, such arrangements wear relatively well.
A variety of methods have been utilized for the attachment of brush materials to substrates such as finishing wheels. For example, strips of crimp channel brush material have been constructed such that they can be mounted on a cylinder, for use in a grinding operation. Tufted brushes have frequently involved a permanent mounting of tufts, in a substrate device adapted for mounting as a wheel or the like, for a finishing operation. Individually set bristle products, such as Brushlon.RTM. products, have been provided on flexible backing, attachable by a variety of means, including hook and loop mounting means (such as Velcro.RTM.), to wheel cylinders etc. for use.
Products other than brushes have been utilized for surface finishing operations, on various materials. These include abrasive flap-wheel arrangements having flaps formed from extensions of fibrous non-woven abrasive material such as Scotchbrite.RTM. abrasive material (3M, St. Paul, Minn. 55144) and elongate sacrificial fibre products. Other finishing devices include grinding wheels, and coated abrasive products such as sandpaper or the like. For any of these three types of arrangements, generally the abrasive material is sacrificed during use, with a final discarding of an associated core or substrate. It is noted that abrasive flap wheels frequently involve rather elongate paddle-like flaps of material, which during rotation of a associated hub, are spun into association with a substrate to be treated.
It is desirable to provide abrasive finishing arrangements wherein the abrasive material can be relatively easily removed or replaced. For non-brush abrasive arrangements, this could generally be accommodated by having a mounting system whereby extensions or flaps of abrasive material can be easily removed and replaced. For brush arrangements, the nature of mounting and the ease with which replacement can be obtained has, generally, depended upon the nature or classification of brush involved.
Crimp channel brush media has been made available in spiral form, so that it can be mounted to a reuseable hub by wrapping the brush tightly around the hub and clamping down ends of the brush.
As previously indicated, arrangements utilizing individual bristles mounted spaced from one another to a flexible substrate have also been provided in removable, replaceable, forms. Most notably, for example, the 3M Brushlon.RTM. product has been provided with a hook and loop mounting system in association therewith, for attachment to wheels or rollers also having hook and loop attachment means thereon. For example, in forming a roll or cylinder brush, an elongate strip of 3M Brushlon.RTM. material might be wrapped spirally about the cylinder.
Non-woven abrasive products are also available in belt form, and have been mounted on expanding rubber wheels or the like. Also, hook and loop mounting systems have been utilized for such products, although generally they have involved mounting on flat surfaces rather than cylinders. Reusable hubs have been used with non-woven abrasive materials, by mounting a series of doughnut-shaped pieces onto a hub with clamping at ends.
One problem with mounting methods that have involved winding of brush material about a hub or the like, is that a considerable length of time, and care, may be needed in order to achieve effective, proper, placement and alignment of brush bristles. For example, in applying 3M Brushlon.RTM. stripping to a roller, substantial down time to the roller device may be necessary while the spiral mounting is accomplished. In some instances, it may even be necessary to remove the roller from the brush equipment, in order to obtain replacement. Similar problems would prevail with many spirally mounted arrangements regardless of the type of brush media involved.
Another problem with spirally wound systems, is that ends of the narrow strands present problems, or weak points, for attachment. Thus, in some instances special anchoring may be necessary at the very ends of the narrow strips; for example, 3M Brushlon.RTM. strips are generally anchored by bolts or the like, at opposite ends. These anchors can provide significant problems for several reasons: first, the anchors may generate a small bald spot in a brush. Secondly, setting of the anchors may require special tools or equipment. Further, the anchors may generate a weak spot, or flaw, in the brush substrate.
For some abrasive cylinder applications, slotted hubs have been developed. An example of such a slotted hub is the 3M RX hub. Slotted hubs will be described in further detail below, with respect to a detailed description of the invention. In general, slotted hubs comprise an elongate cylinder having a plurality of longitudinal slots around the outer surface of the cylinder. Each slot is sized and oriented for anchoring of material thereto. Although a variety of arrangements may be utilized, in general in accord with industry standards and general agreement, about five slots per inch outside diameter have been frequently used.
Crimped channel or strip brushes are sometimes mounted in slotted hubs. In general, the crimp or strip, having bristles extending therefrom, is slid, longitudinally, into one of the cylinder channels and is retained therein. Retention is frequently accomplished through use of a channel having a wide internal portion and a narrow neck; with the brush material being anchored in a relatively wide root of material. The brush material can be slid longitudinally into the slot, with radial separation from the hub being basically impossible due to interference, but with longitudinal separation being relatively simple to achieve.
The common type of finishing wheel arrangement using a slotted hub, is one wherein the replaceable segments comprise abrasive flap segments. Each group of abrasive flaps is generally mounted to a root, which is anchored to the slotted hub. Examples of these include products marketed by 3M under the designations RX and RXC. RX segments contain coated abrasive flaps and RXC segments contain non-woven Scotchbrite.RTM. abrasive material, as well as coated abrasive flaps.
In many conventional applications of longitudinal slotted hubs, each abrasive member is mounted on a single root. The abrasive members are such that each abrasive member/root combination is capable of a certain amount of hinged movement, or pivoting movement, (i.e. flapping) with respect to the hub itself.
What has been needed has been a method and arrangement whereby a brush arrangement comprising a carpet-like arrangement of bristles, i.e. tufted or preferably individually anchored bristle arrangements, can be securely mounted in a slotted arrangement, for use as a cylindrical brush or the like. What has been particularly needed has been an arrangement whereby mounting, removal and replacement of brush material may be rather readily effected.